The invention pertains to a vessel for storing particulate matter, such as pulverised coal or fly ash.
Such vessels are employed inter alia for (temporary) storage of pulverised coal and fly ash in coal gasification plants. Coal gasification is known in the art and involves the partial combustion of carbonaceous materials such as coal and petroleum coke. The primary product is syngas, a mixture of carbon monoxide and hydrogen, which is often used to manufacture pure hydrogen and to synthesise ammonia, methanol, oxo chemicals and their derivatives, such as urea fertiliser and synthetic hydrocarbon fuels. Syngas can also be used directly as a fuel to generate heat, steam and electricity.
U.S. Pat. No. 5,129,766 (in the name of Shell Oil Company) discloses a vessel comprising a feed hopper (numeral 11 in FIG. 1) and a cone-shaped “receiving means 7”. According to U.S. Pat. No. 5,129,766, it is of particular importance in the manufacture of synthesis gas that particulate fuel is introduced to burners within the gasifier in a uniform manner. Fluctuations in the mass flow rate of coal being supplied to the burners of the gasifier are detrimental to its performance.
FIG. 2 of U.S. Pat. No. 5,129,766 shows a receiving means (7) which may be lined with a liner or inner shell (8) whose walls may be permeable, or porous, to gaseous fluids used for aerating the mixture of particulate solids and gas present in the receiving means. A jacket (13) surrounds the liner (8) and is mounted to form a substantially enclosed space between the walls (12) of the liner (8) and the jacket (13). As can be seen from FIG. 2, the receiving means (7) comprises a flange, which is connected, by means of bolts, to a flange on the bottom side of the feed hopper. The liner (8) is kept in place by clamping a flange forming the upper rim of the liner (8) between the said flanges on the receiving means (7) and the feed hopper (11).
As a result of this construction, extra leaks paths are created from the (pressurised) feed hopper to the atmosphere and small deviations in the position of the liner or the flanges may subject the liner to detrimental bending stresses, especially during bolt tightening. It is an object of the present invention to reduce at least one of these effects.